Mike Conley and Marreese Speights each scored 15, Gilbert Arenas had 12 and Marc Gasol and O.J. Mayo each added 10 for the Grizzlies, who have won six of their last eight games.

LeBron James finished with 21 points, six assists and six rebounds for the Heat, who never led and failed in a bid to match the franchise's longest home win streak, set in the 2004-05 season.

Dwyane Wade scored 20 points, Chris Bosh added 19 and Terrel Harris scored 10 for Miami, which last lost at home on Jan. 22 to Milwaukee.

It was the second time in two weeks that Memphis got seven players into double figures. Another good sign for the Grizzlies: Arenas had been 3 for 13 from 3-point range in his first six games with Memphis, but was 4 for 5 on Friday.

Miami (39-15) fell three games behind Chicago (43-13) in the race for the No. 1 seed in the Eastern Conference. The Heat have 12 games left, the Bulls have 10, and the teams go head-to-head twice more before the postseason begins.

Memphis came into the night only two games out of fourth in the Western Conference, and coach Lionel Hollins talked beforehand about the importance of getting sharper heading into the postseason.

His team must have listened, because it came out flying.

The Grizzlies forced 11 turnovers in the first quarter -- Miami's most in a quarter since Feb. 14, 2006 -- and led 25-12 behind nine points from Gay. By halftime, the lead was 48-32, the second-lowest scoring first half for the Heat since the first game of the Big Three era, the opener at Boston last season.

Just about every number imaginable for the Heat in the early going was bad.

Wade missed two dunks in the first half, shooting 1 for 7. Midway through the second quarter, Bosh was shooting 4 for 5 and Harris 2 for 2 off the bench -- while everyone else in a Miami uniform was shooting 1 for 17 at that point. And the Heat finished the half shooting 33 percent, dropping them to 38 percent in their last eight quarters, all at home.

There were chances in the third for Miami to get the lead into single digits, all of them thwarted.

The first one came when Conley stole the ball from Mario Chalmers, a sequence capped by Quincy Pondexter getting a dunk. And then about 3 minutes later, Miami endured maybe its most frustrating possession of the night.

James spun and tried a left-handed layup with 4:25 left in the third, the ball rimming out but Miami's possession extended when Joel Anthony was fouled going for the rebound. James then attacked the lane for a jumper that missed, with the Heat getting that rebound as well and Harris finding James underneath the rim.

His layup -- his third shot of the possession -- came up short, a microcosm of Miami's night.

Arenas' fourth 3-pointer of the night came with 9:40 left, giving the Grizzlies an 81-64 lead. Conley stretched the lead to 86-66 with another 3-pointer midway through the fourth, and after James grabbed his hand in pain after Miami thought he got fouled, Heat coach Erik Spoelstra picked up a technical foul in frustration.

Game notes
Memphis' 13-point edge was the biggest lead by a visitor in Miami after the first quarter since San Antonio led 29-14 after the opening 12 minutes at the Heat on March 16, 2010. ... Memphis guard Tony Allen was not with the Grizzlies, out because of a facial laceration suffered in Dallas on Wednesday night. ... Harris, who has impressed the Heat of late, got first-quarter minutes for just the third time this season.